The field of this disclosure relates generally to systems and methods for data reading and/or image capture, and more particularly, to illumination systems particularly applicable to imaging data readers.
Data reading devices are used to read optical codes, acquire data, and capture a variety of images. Optical codes typically comprise a pattern of dark elements and light spaces. There are various types of optical codes, including one-dimensional codes, such as a Universal Product Code (“UPC”) and EAN/JAN codes, and stacked and two-dimensional codes, such as PDF417 and Maxicode codes.
Data reading devices are well known for reading UPC and other types of optical codes on packages, particularly in retail stores. One common data reader in such systems is an imaging reader that employs an imaging device or sensor array, such as a CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) device. Imaging readers can be configured to read both 1-D and 2-D optical codes, as well as other types of optical codes or symbols and images of other items. Though some imaging readers are capable of using ambient light illumination, an imaging reader typically utilizes a light source to illuminate the item being read to provide the required signal response in the imaging device. An imager-based reader utilizes a camera or imager to generate electronic image data, typically in digital form, of an optical code. The image data is then processed to find and decode the optical code.
In both laser-based and imager-based types of readers, dual plane or bioptic style readers (e.g., readers with a horizontal window and a vertical window) are popular for high volume applications because they provide multiple perspectives or fields of view into the read region. These readers typically have bright illumination sources that are potentially distracting to the operator. Thus the present inventors have recognized that it is desirable to minimize bright light from the illumination sources of these readers from reaching or interfering with the sight lines of the operator or the customer.